. >> sreenivasan: the state of california held its first auction today of greenhouse gas pollution permits. the cap-and-trade plan is a key part of the state's global warming law enacted in 2006. under its provisions, businesses must cut emissions to a certain level or buy allowances from companies that don't need all of their allowances. the program still has to survive a court challenge. the u.s. air force will change the way it selects officers and instructors who train new recruits. that follows a sexual abuse scandal at lackland air force base near san antonio, texas. an investigation found 23 instructors allegedly abused at least 48 female recruits. so far, five people have been convicted on charges ranging from adultery to rape. those are some of the day's major stories. now, back to judy. >> woodruff: and we turn back to one of the topics raised in president obama's news conference today, the investigation of former c.i.a. director david petraeus. the former military leader's resignation after admitting to an extramarital affair raises questions about the standards americans hold u